The purpose of this research is to develop synthetic methods for the preparation of the naturally occurring cancer chemotherapeutic agents vincristine (leurocristine) and vinblastine (vincaleukoblastine). The synthetic approach to these dimeric indole alkaloids will involve studies of: a) the synthesis of appropriate monomers; b) the dimerization of indoles; and c) the synthesis of derivatives and models of vincristine and vinblastine.